BLBS102-c05 BLBS102-Simpson March 21, 2012 12:2 Trim: 276mm X 219mm Printer Name: Yet to Come
5
Water Chemistry and Biochemistry
C. Chieh
Introduction
The Compound Water
The Polar Water Molecules
Water Vapor Chemistry and Spectroscopy
Hydrogen Bonding and Polymeric Water in Vapor
Condensed Water Phases
Solid H 2 O
Other Phases of Ice
Vapor Pressure of Ice Ih
Liquid H 2 O—Water
Vapor Pressure of Liquid H 2 O
Transformation of Solid, Liquid, and Vapor
Subcritical and Supercritical Waters
Aqueous Solutions
Colligative Properties of Aqueous Solutions
Solution of Electrolytes
Self-Ionization of Water
Solutions of Acids and Bases
Titration
Solutions of Amino Acids
Solutions of Salts
Buffer Solutions
Hydrophilic and Hydrophobic Effects
Hard Waters and Their Treatments
Ionic Strength and Solubility of Foodstuff
Water as Reagent and Product
Esterification, Hydrolysis, and Lipids
Water in Digestion and Syntheses of Proteins
Water in Digestion and Synthesis of Carbohydrates
Water, Minerals, and Vitamins
Food Chemistry of Water
Water as a Common Component of Food
Water Activity
Aquatic Organisms and Drinking Water
Water and State of FoodModified fromHandbook of Water Chemistry, copyright 2004©by Chung
Chieh. Used with permission.Interaction of Water and Microwave
Water Resources and the Hydrological Cycle
Acknowledgments
ReferencesINTRODUCTION
Water, the compound H 2 O, is the most common food ingredient.
Its rarely used chemical names are hydrogen oxide or dihydrogen
monoxide. So much of this compound exists on the planet earth
that it is often taken for granted. Water is present in solid, liquid,
and gas forms in the small range of temperatures and pressures
near the surface of the earth. Moreover, natural waters always
have substances dissolved in them, and only elaborate processes
produce pure water.
The chemistry and physics of water are organized studies of
water: its chemical composition, formation, molecular structure,
rotation, vibration, electronic energies, density, heat capacity,
temperature dependency of vapor pressure, and its collective
behavior in condensed phases (liquid and solid). In a broader
sense, the study of water also includes interactions of water with
atoms, ions, molecules, and biological matter. The knowledge of
water forms the foundation for biochemistry and food chemistry.
Nearly every aspect of biochemistry and food chemistry has
something to do with water, because water is intimately linked
to life, including the origin of life.
Science has developed many scientific concepts as powerful
tools for the study of water. Although the study of water reveals
a wealth of scientific concepts, only a selection of topics about
water will be covered in the limited space here.
Biochemistry studies the chemistry of life at the atomic and
molecular levels. Living organisms consist of many molecules.
Even simple bacteria consist of many kinds of molecules. The
interactions of the assembled molecules manifest life phe-
nomena such as the capacity to extract energy or food, re-
spond to stimuli, grow, and reproduce. The interactions followFood Biochemistry and Food Processing, Second Edition. Edited by Benjamin K. Simpson, Leo M.L. Nollet, Fidel Toldr ́a, Soottawat Benjakul, Gopinadhan Paliyath and Y.H. Hui.
©C2012 John Wiley & Sons, Inc. Published 2012 by John Wiley & Sons, Inc.84